1. Field of the Invention
The invention relates to a lithography apparatus and a lithography method and, for example a lithography method and apparatus which writes a pattern on a target object using an electron beam.
2. Related Art
A lithography technique which advances the development of micropatterning of a semiconductor device is a very important process, the only process to generate a pattern in semiconductor manufacturing processes. In recent years, as integration density increases in LSIs, a circuit line width requested for a semiconductor device is miniaturized year by year. In order to form a desired circuit pattern for the semiconductor device, a high-precision original pattern (also called a reticle or a mask) is necessary. In this case, an electron beam pattern writing technique primarily has an excellent resolution, and is used in manufacture of a high-precision original pattern.
FIG. 7 is a conceptual diagram for explaining an operation of a variable-shaped electron beam lithography apparatus.
The variable-shaped electron beam (EB) lithography apparatus operates as described below. In a first aperture plate 410, a square, for example, rectangular opening 411 to shape an electron beam 330 is formed. In a second aperture plate 420, a variable-shaped opening 421 to shape the electron beam 330 passing through the opening 411 into a desired square shape is formed. The electron beam 330 irradiated from a charged particle source 430 and passing through the rectangular opening 411 is deflected by a deflector. The beam passes through a part of the variable-shaped opening 421 and is irradiated on a target object which is placed on a stage and coated with a resist material. The stage continuously moves in one predetermined (for example, an X direction) during pattern writing. In this manner, a square shape which can pass through both the rectangular opening 411 and the variable-shaped opening 421 is written on a pattern writing region of the target object 340. A scheme that causes a beam to pass through both the opening 411 and the variable-shaped opening 421 to form an arbitrary shape is called a variable-shaped scheme.
An identifying (ID) figure to identify a mask itself is written outside a chip region for manufacturing an original semiconductor of a mask serving as a target object. For example, the figure is written by a bar-code pattern (for example, see JP-A-2001-92110). For example, when the mask is to be written, an ID figure to identify the mask itself described above is written together with a pattern to manufacture an original semiconductor at the same time. In a conventional art, to write the ID figure, a graphic data representing an ID figure is formed by using a CAD or the like in advance. The graphic data for the ID is formed by the same format as that of a pattern data for manufacturing an original semiconductor. However, the ID figure is unique to the mask. Different ID figures are used different masks. For this reason, the graphic data for the ID must be cumbersomely formed for each mask. Since the ID figure is formed by using a CAD or the like in advance, information obtained immediately before pattern writing, information such as a time of day of actual pattern writing, and the like cannot be described. However, for a user side, the information obtained immediately before pattern writing is strongly required to be written in a mask as an ID figure.
As described above, the information obtained immediately before is strongly required to be written as the ID figure on the mask. However, as in pattern data for manufacturing a semiconductor, graphic data representing the ID figure must be additionally formed by an external apparatus or the like in advance, and the information obtained immediately before the pattern writing is difficult to be included in the ID figure.